The restoration of endogenous insulin secretion carries significant hopes for shifting the paradigm of life long exogenous insulin therapy in selected groups of patients with type 1 diabetes(T1D). After decades of frustrating clinical attempts, the Edmonton group set up in 2000 new standards for islet transplantation in patients with brittle T1D by achieving insulin independence in 80 percent of patients. These seminal results have however proved much more difficult to duplicate than initially expected.